Immunoprotective Encapsulation of Micro-Organs

Abstract

Background: Cell encapsulation technology is most likely the ultimate solution for cell therapy based clinical approaches. A key issue when developing a functional encapsulated construct is to consider not only the nature of the capsule but also how the cells should be incorporated into the capsule in order to minimally compromise their function. Methods: We have developed a tissue engineering approach, composed of decellularized micro scaffolds and various types of cells in which fully functional "Engineered Micro-Organs" (EMOs) are formed. Based on this technology, Engineered Micro-Pancreata (EMPs), made by seeding human islets into acellular micro-scaffolds, have been shown to remain viable, and to secrete high levels of insulin in a regulated manner as a function of glucose comparable to those secreted by fresh human islets in culture for long periods. We now report the development of a novel encapsulation approach that takes into account the structure and diffusion requirements of the encapsulated construct. Results: We here report the development of a capsule in which encapsulated EMPs, when implanted into xenogeneic mice, induced the formation of a fine vascular network and continued to secrete human insulin in a glucose regulated manner for several weeks.